单模光纤全金属化耦合封装1．3μm侧面发光二极管

阐述了１．３μｍ侧面发光二极管（ＥＬＥＤ）到单模光纤的耦合和实验结果。获得了在１００ｍＡ的驱动电流下，对于芯径为８～１０μｍ的标准单模光纤，最大尾纤输出功率大于５０μＷ，典型值２０μＷ的同轴式、扁平式、１４针双列直插式的全金属化耦合封装器件具有较高的可靠性和温度稳定性。

双电流限制结构的1.55μm单模全金属化耦合封装激光二极管

叙述了具有双电流限制结构的1.55μm InGaAsP/InP 隐埋新月形激光器的制造工艺和主要特性。在室温 CW 工作条件下,该激光二极管的最低阈值电流为20mA,典型值为30mA。可在2～3倍阈值电流下获得稳定的基横模输出。在室温 CW 工作下,管芯的最大光输出功率大于10mW。激光器组件由半导体致冷器,热敏电阻和 PIN 探测器组成,采用了标准的14针双列直插式管壳,实现了激光器组件的全金属化耦合封装,漏气率小于5×10^(-3)Pa·cm^2/s,尾纤输出功率典型值为1mW。

Dual-Work-Function Ni-FUSI Metal Gate for CMOS Technology

This paper investigates the work function adjustment of a full silicidation （Ni-FUSI） metal gate. It is found that implanting dopant into poly-Si before silicidation can modulate the work function of a Ni-FUSI metal gate efficiently. With the implantation of p-type or n-type dopants,such as BF2 ,As,and P,the work function of a Ni-FUSI metal gate can be made higher or lower to satisfy the requirement of pMOS or nMOS, respectively. But implanting a high dose of As into a poly-Si gate before silicidation will cause the delamination effect and EOT loss,and thus As dopant is not suitable to be used to adjust the work function of a Ni-FUSI metal gate. Due to the EOT reduction in the FUSI Process,the gate leakage current of a FUSI metal gate capacitor is larger than that of a poly-Si gate capacitor.

Design of p-n homojunctions in metal-free carbon nitride photocatalyst for overall water splitting

Two-dimensional(2D)carbon nitride(CN)photocatalysts are attracting extensive attention owing to their excellent photocatalytic properties.In this study,we successfully prepared CN materials with heterogeneous structures via hydrothermal treatment,high-temperature roasting,ball milling,sintering,and other processes.Benefitting from interface interactions in hybrid architectures,the CN photocatalysts exhibited high photocatalytic activity.The rate of hydrogen production using these CN photocatalysts reached 17028.82μmol h^(−1)g^(−1),and the apparent quantum efficiency was 11.2%at 420 nm.The ns-level time-resolved photoluminescence(PL)spectra provided information about the time-averaged lifetime of fluorescence charge carriers;the lifetime of the charge carriers causing the fluorescence of CN reached 9.99 ns.Significantly,the CN photocatalysts displayed satisfactory results in overall water splitting without the addition of sacrificial agents.The average hydrogen and oxygen production rates were 270.95μmol h^(−1)g^(−1)and 115.21μmol h^(−1)g^(−1)in 7 h,respectively,which were promising results for the applications of the catalysts in overall water splitting processes.We investigated the high efficiency of the prepared CN photocatalysts via a series of tests(UV-vis diffuse reflectance spectroscopy,photocurrent response measurements,PL emission spectroscopy,time-resolved PL spectroscopy,and Brunauer-Emmett-Teller analysis).Furthermore,the Mott-Schottky plot and current-voltage curve were acquired via electrochemical tests.The fabricated CN photocatalyst had a small p-n junction in its heterogeneous structure,which further enhanced its photocatalytic efficiency.Therefore,this work can promote the development of CN photocatalysts.

New Design Methodologies for High Speed Low-Voltage 1-Bit CMOS Full Adder Circuits

New methodologies for l-Bit XOR-XNOR full- adder circuits are proposed to improve the speed and power as these circuits are basic building blocks for ALU circuit implementation. This paper presents comparative study of high-speed, low-power and low voltage full adder circuits. Simulation results illustrate the superiority of the proposed adder circuit against the conventional complementary metal-oxide-semiconductor （CMOS）, complementary pass-transistor logic （CPL）, TG, and Hybrid adder circuits in terms of delay, power and power delay product （PDP）. Simulation results reveal that the proposed circuit exhibits lower PDP and is more power efficient and faster when compared with the best available 1-bit full adder circuits. The design is implemented on UMC 0.18 μm process models in Cadence Virtuoso Schematic Composer at 1.8 V single ended supply voltage and simulations are carried out on Spectre S.

A 150 mV-1.2 V Fully-Integrated DC-DC Converter for Thermal Energy Harvesting

With the increasing use of low voltage portable devices and wireless systems, energy harvesting has become an attractive approach to overcome the problems associated with battery life and power source. Among the different types of microenergy scavengers, the TEG （thermoelectric generators） are one of the most commonly used one. Unfortunately, due to the very small amount of voltage delivered by the TEG, an efficient DC/DC （direct current/direct current） conversion and power management techniques are needed. In this paper, a CMOS （complementary metal oxide semiconductor） fully-integrated DC/DC convener for energy harvesting applications is presented. The startup-voltage of the converter is about 140 mV, the output voltage exceeds 1.5 V, with a 20% power efficiency at least. The architecture for boosting such extremely low voltages is based on an ultra-low-voltage oscillator cross connected to two phase charge pump. The overall circuit does not require any external components and can be fully integrated in a standard CMOS low voltage technology. A test-chip has been designed in UMC （united microelectronics corporation） 180 nm CMOS process.

Heat and Radiation Generation during Hydrogenation of CH Compound

Securing new sources of energy has become a major concern, because fossil fuels are expected to be depleted within several decades. In some of the major wars of the 20th century, control of oil was either a proximate cause or a decisive factor in the outcome. Especially in Japan and Germany, a great deal of research was devoted to making liquid fuels from coal. In one such experiment, a large amount of excess heat was observed. The present study was devoted to replicating and controlling that excess heat effect. The reactant is phenanthrene, a heavy oil fraction, which is subjected to high pressure and high heat in the presence of a metal catalyst. This results in the production of excess heat and strong penetrating electromagnetic radiation. After the reaction, an analysis of residual gas reveals a variety of hydrocarbons, but it seems unlikely that these products can explain the excess heat. Most of them form endothermically, and furthermore heat production reached 60 W. Overall heat production exceeded any conceivable chemical reaction by two orders of magnitude.

Pt embedded Ni3Se2@NiOOH core-shell dendrite-like nanoarrays on nickel foam as bifunctional electrocatalysts for overall water splitting

Developing high-performance bifunctional catalysts toward hydrogen evolution reaction(HER) and oxygen evolution reaction(OER) is essential to enhance water splitting efficiency for large-scale hydrogen production. Neither noble metal Pt nor transition metal compounds show satisfactory performances for both HER and OER simultaneously. Here, we prepared a three-dimensional Pt-Ni3 Se2@NiOOH/NF(PNOF) hybrid catalyst via in-situ growth strategy. Benefitting from the self-supported structure and oxygen vacancies on the surface of NiOOH nanosheets, the PNOF electrode shows remarkably catalytic performance for dual HER and OER. The overall water electrolyzer using PNOF as anode and cathode can achieve a current density of10 mA cm^-2 at a low voltage of 1.52 V with excellent long-term stability, which is superior to precious metal catalysts of Pt/C and Ir/C. This study provides a promising strategy for preparing bifunctional catalysts with high performance.

Cobalt-vanadium bimetal-based nanoplates for efficient overall water splitting

The development of effective and low-cost catalysts for overall water splitting is essential for clean production of hydrogen from water.In this paper,we report the synthesis of cobalt-vanadium（Co-V）bimetal-based catalysts for the effective water splitting.The Co_2V_2O_7·xH_2O nanoplates containing both Co and V elements were selected as the precursors.After the calcination under NH_3atmosphere,the Co_2VO_4and Co/VN could be obtained just by tuning the calcination temperature.Electrochemical tests indicated that the Co-V bimetal-based materials could be used as active hydrogen evolution reaction（HER）and oxygen evolution reaction（OER）catalyst by regulating their structure.The Co/VN showed good performance for HER with the onset potential of68 mV and can achieve a current density of 10 mA cm^（-2）at an overpotential of 92 m V.Meanwhile,the Co_2VO_4exhibited the obvious OER performance with overpotential of 300 mV to achieve a current density of 10 mA cm^（-2）.When the Co_2VO_4and Co/VN were used as the anode and cathode in a twoelectrode system,respectively,the cell needed a voltage of1.65 V to achieve 10 mA cm^（-2）together with good stability.This work would be indicative to constructing Co-V bimetalbased catalysts for the catalytic application.

C–H bond activation in the total syntheses of natural products

The transition metal-mediated C–H bond activation has emerged as a powerful and ideal method for the total syntheses of natural products and pharmaceuticals, and has had a significant impact on synthetic planning and strategy in complex natural products.In this review, we describe selected recent examples of the transition metal-mediated C–H bond activation strategies for the rapid syntheses of natural products.

New electrochemical energy storage systems based on metallic lithium anode the research status,problems and challenges of lithium-sulfur,lithium-oxygen and all solid state batteries

Li-ion batteries have played a key role in the portable electronics and electrification of transport in modern society. Nevertheless,the limited highest energy density of Li-ion batteries is not sufficient for the long-term needs of society. Since lithium is the lightest metal among all metallic elements and possesses the lowest redox potential of.3.04 V vs. standard hydrogen electrode, it delivers the highest theoretical specific capacity of 3860 mA h g^(-1) and a high working voltage of full batteries which causes a great interest in electrochemical energy storage systems. Lithium-sulfur, lithium-oxygen and corresponding all solid state batteries based on metal lithium anode have received widely attention owing to their high energy densities. However, the problems in the cathode,electrolyte and anode of these three systems restrict their practical application. In this review, the research status and problems of these three energy storage systems are summarized and the challenges and future perspectives are also outlined.

Enhancing the reversible capacity and cycle stability of lithium-ion batteries with Li-compensation material Li_(6)CoO_(4)

High-capacity anode materials,such as SiO and Si/C,are considered promising candidates for high-energydensity lithium-ion batteries.However,the low initial Coulombic efficiency of these anode materials induced by side reactions(forming Li_(2)O and lithium silicate)and the formation of solid electrolyte interface film reduces the active Liions and causes low-discharge capacity.Adding a Li-compensation material in the cathode or anode is an effective strategy to overcome this problem.The most used Li-compensation material is the stabilized lithium metal powder.However,this strategy has high safety risks,high costs,and is challenging to quantify.Herein,the Li-compensation material of Li_(6)CoO_(4) is synthesized and investigated.The preparation conditions,stability in the air,delithiation mechanism,and structural transformation are analyzed and discussed.Electrochemical tests reveal that the discharge capacity and capacity retention of the full pouch cells(3-Ah)with Li_(6)CoO_(4) additive is significantly improved.Also,the reason for such improvement is investigated.This work provides an effective strategy of Li-compensating technology to enhance the electrochemical performance of lithium-ion batteries.